1. Field of the Invention
The invention relates to a process for winding a material web produced from a pulp suspension and finally dried, e.g., a paper or cardboard web, onto a reel spool to produce a wound reel, in which the material web is smoothed “online” and is then conducted over a reel drum. A winding nip is formed between the reel drum and the reel spool, and the reel drum and the wound reel being formed are held in contact with one another during the winding procedure.
The invention further relates to a winding machine for winding a material web produced from a pulp suspension and finally dried, e.g., a paper or cardboard web, onto a reel spool to produce a wound reel, in which the material web is smoothed “online” and is then conducted over a reel drum. A winding nip is formed between the reel drum and the reel spool, and the reel drum and the wound reel being formed are held in contact with one another during the winding procedure.
2. Discussion of Background Information
Such a process and such a winding machine are known, e.g., from the published European Application No. EP 0 483 092 A1. They are used, e.g., at the end of a machine for producing or finishing a material web. However, they can also be used to rewind an already fully wound reel. The machine in question can be, e.g., a paper or cardboard machine.
From the commonly owned International Publication No. WO 95/30049, of which U.S. Pat. No. 5,685,909 was a U.S. National Stage application, a process and a winding machine are also known for producing paper webs coated bilaterally inside a paper machine in which the coated paper web is smoothed by at least one online calender and is then wound onto a reel spool to produce a wound reel.
Furthermore, in the commonly owned German Utility Model Patent No. DE 297 21 832.8, a device is disclosed for optionally smoothing coated or uncoated material webs, such as, paper or cardboard, that are at least partially dried in the drying section of a paper machine. The disclosed device includes at least one web guide roll, at least one calender, and a reeling device.
Experiments that have been performed have now revealed that, after the online smoothing, irregularities can occur in cross profiles, such as, in particular, in the thickness cross profile of a material web, where the average thickness of the material web is also reduced to about 70 to 30% of its original thickness. These irregularities generally occur only occasionally, in particular in the case of a paper machine, because irregularities can be eliminated, e.g., by adjusting the headbox. Nevertheless, they can have a detrimental effect on the symmetry of the winding construction. Therefore, the result may be that the winding diameter on one side of the material web width is, e.g., larger than the desired diameter. The winding construction is then no longer cylindrical. Moreover, it also results frequently in an undesired overstretching of the material web, which can, e.g., have a considerable effect on the flatness of graphic papers.